Well,you got me to thinking about this. I guess that loading of the libs is what used to get the .H files in the right place and telling the compiler that they exist. So I decided why not try it even though there is no lib folder. I took the whole mysensors 2.1.1 folder and told the library manager to add it. No errors. I then went into the library manager and it said 2.1.1 was in fact installed. Loaded up GatewaySerial and it compiled fine with board of UNO, Nano and nodeMCU.

Loaded it onto a nodeMCU and it is running. In the serial monitor I can see messages from the board. It is indicating some problem with initialization but that is another thread.

I really, really thank you for giving me some ideas.

Ultimately I'm trying to add some adruino sensor devices to my HomeSeer system. There is a mysensors plugin for HomeSeer. That is a multi step process but getting a cleanly compiled program to run on a wifi enabled device is a major step. Hopefully the nodeMCU will work out as well as it looks. Next step is to get the mysensors plugin installed in HomeSeer and get everybody to talk to each other.

New to Arduino. I'm trying to create a serial gateway. I have a genuine UNO with a 8266 WIFI. Hopefully wired correctly. I did it per the MySensors serial gateway video.

I've downloaded Arduino IDE ver 1.8.2 and MySensors ver 2.1.1. I can compile the Arduino example blink and it loads and runs fine. When I try to compile GatewaySerial I get errors. I suspect I don't have things in the right place. Hopefully the errors below will be something that is just a common mistake.